Hermetic packages formed from ceramics are commonly used for semiconductor applications requiring high performance and high reliability. Hermetic sealing prevents gases and moisture from entering cavities within the hermetic packages where semiconductor dies are mounted. In addition, ceramic materials used in the hermetic packages withstand higher temperatures than a traditional plastic package and provide low Coefficient of Thermal Expansion (CTE) for the semiconductor die.
Typically, a conventional hermetic package has an un-grounded floating metallic ring on the top of a substrate. This metallic ring is needed for the eutectic Gold/Tin (Au/Sn) solder hermetic seal. However, the ungrounded floating feature of the metallic ring may lead to unwanted radio frequency (RF) coupling between input and output of the hermetic package, lead to instability of the semiconductor die, and render the package useless beyond a certain frequency of operation.
Accordingly, there remains a need for improved hermetic package designs that suppress the unwanted RF coupling and increase the stability of the semiconductor die. In addition, there is also a need to keep the final product cost and size effective.